Analog Devices Inc. EVAL-AD7798EBZ

Overview

EVAL-AD7798EBZ from Analog Devices is a USB-powered evaluation board designed exclusively for the AD7798 16-bit, low-power, sigma-delta analog-to-digital converter with three differential input channels, on-board ADP3303 3.3 V regulator, and integrated temperature demonstration circuit using a 1 kΩ thermistor and 5 kΩ precision resistor.

For engineers reviewing the EVAL-AD7798EBZ datasheet, EVAL-AD7798EBZ pinout, EVAL-AD7798EBZ application, or EVAL-AD7798EBZ equivalent, this board enables rapid functional validation of the AD7798's 4.17 Hz–470 Hz programmable update rate, ±VREF/gain analog input range (gain 1–128), simultaneous 50/60 Hz rejection, and low-side power switch control-without external clock or reference components.

Technical Context

The EVAL-AD7798EBZ implements a complete hardware interface between an IBM-compatible PC and the AD7798 ADC via a Cypress CY7C68013A USB controller, supporting SPI communication over USB with no driver installation required beyond bundled software. It provides configurable analog signal routing through 10 user-settable links (LK1–LK10) and five SMB connectors (AIN1±, REFIN±) plus an 18-pin header (J2) for custom prototyping.

Power is flexibly supplied via USB (5 V), on-board ADP3303 (3.3 V), or external source (3 V/5 V via J3). The board supports ratiometric temperature measurement using LK3–LK6, noise analysis via shorted AIN1± (LK1/LK2), and LED-based low-side switch verification (LK10/D2), all controlled through LabVIEW-based PC software with Registers, Temp Demo, and Quick Analysis windows.

Key Specifications

Availability

EVAL-AD7798EBZ is available at Aetrix Electronics and suitable for precision sensor interface validation, industrial process monitoring, and low-frequency data acquisition system development requiring stable component supply and full technical documentation support.

Supply support for EVAL-AD7798EBZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA, with design and manufacturing expertise spanning precision data conversion, power management, and RF technologies.

The EVAL-AD7798EBZ belongs to Analog Devices' precision ADC evaluation platform family, engineered to accelerate design-in of low-power, high-resolution sigma-delta converters for sensor signal conditioning, weigh scales, medical instrumentation, and environmental monitoring applications.

FAQ

What is the primary function of the EVAL-AD7798EBZ?

The EVAL-AD7798EBZ is a dedicated evaluation board for the AD7798 16-bit sigma-delta ADC. It provides a complete, USB-powered hardware and software environment to configure, test, and validate the AD7798's performance-including its three differential input channels, programmable gain (1–128), 4.17 Hz–470 Hz update rate, and on-chip low-side power switch-without requiring external clocks or references. The EVAL-AD7798EBZ enables immediate functional verification prior to system integration.

Does the EVAL-AD7798EBZ require an external power supply?

No, the EVAL-AD7798EBZ operates directly from the 5 V USB supply (J1) and includes an on-board ADP3303 3.3 V regulator (U4) to power the AD7798. An external 3 V or 5 V supply can be used via terminal block J3 if needed, but it is not required. Power source selection for AVDD is controlled by link LK9 (positions A/B/C), making the EVAL-AD7798EBZ fully self-contained for bench evaluation.

How does the EVAL-AD7798EBZ support temperature measurement?

The EVAL-AD7798EBZ integrates a ratiometric temperature demonstration circuit: inserting links LK3–LK6 connects a 1 kΩ thermistor to AIN2(±) and a 5 kΩ precision resistor to the AD7798 reference pins (REFIN±), both referenced to AVDD. The bundled LabVIEW software automatically configures the AD7798 (gain = 1, AIN2 channel) and converts raw codes to temperature using an internal lookup table-enabling immediate ambient temperature sensing without external components or calibration.

Can the EVAL-AD7798EBZ be used for noise analysis?

Yes, the EVAL-AD7798EBZ supports noise analysis via links LK1 and LK2, which short AIN1(+) and AIN1(−) to AVDD/2 to create a zero-differential-input condition. With this configuration, users can collect multiple samples at any supported update rate (e.g., 16.7 Hz default) and compute rms noise (e.g., 85 nV at gain 64), histogram distribution, and effective resolution-all within the included software's Sample, Histogram, and Waveform functions.

What software is provided with the EVAL-AD7798EBZ?

The EVAL-AD7798EBZ ships with Windows-based LabVIEW-compatible software that provides full register-level control (Configuration, Mode, IO, Offset, Full-Scale), real-time data capture, temperature demonstration, and Quick Analysis for gain/update rate/channel tuning. It supports data export to Excel or MathCAD, automatic device reset to power-up defaults, and continuous sampling with configurable Num Samples-enabling comprehensive characterization of the AD7798 without writing custom firmware or drivers.